Conventionally, a turret punch press is known as a device for punching and forming of plate form work. In this type of arrangement, a plurality of dies are required to be set in a turret prior to commencing operation.
A plurality of patent applications have been filed with respect to the various components of this type of device.
For example, Japanese Examined Patent Publication (Kokoku) No. 54-17973, Japanese Examined Patent Publication No. 54-6751, Japanese Unexamined Patent Publication (Kokai) No. 56-119626, Japanese Unexamined Patent Publication No. 60-106630 and Japanese Unexamined Patent Publication No. 60-106631 disclose technologies for positioning and exchanging of dies.
On the other hand, for example, Japanese Unexamined Patent Publication No. 63-130225, Japanese Unexamined Patent Publication No. 63-130226, Japanese Unexamined Patent Publication No. 63-130227, Japanese Unexamined Patent Publication No. 63-130228, Japanese Examined Utility Model Publication No. 64-3546, Japanese Unexamined Utility Model Publication No. 62-127318 and Japanese Examined Patent Publication No. 59-44940 disclose technologies for controlling strokes of upper dies or for rotating turrets.
All of these technologies relate to the turret punch press. The turret punch press includes upper and lower turrets which rotate in synchronism with each other. However, the construction which controls this synchronous rotation is complicated and expensive.